… and it means “Keep It Short, Stupid” as much as it does “Keep It Simple, Stupid.”

Regardless of the era, most successful copywriters and ad specialists have always known that short copy is generally better-read than long.

And now, as smaller screens essentially take over the digital world, the days of copious copy flowing across a generous preview pane area are gone.

More fundamentally, people don’t have the screen size – let along the patience – to wade through long copy. These days, the “sweet spot” in copy runs between 50 and 150 words.

Speaking of which … when it comes to e-mail subject lines, the ideal length keeps getting shorter and shorter. Research performed by SendGrid suggests that it’s now down to an average length of about seven words for the subject line.

And the subject lines that get the best engagement levels are a mere three or four words.